Biomedical subjects

J Peters

Publications and source records attributed to J Peters.

At least 217 records · Page 12Linked to original sources

PubMed1998

[The importance of bronchial hyperreactivity in anesthesiology].

Airways of patients with bronchial hyperreactivity (BHR) are characterised by exaggerated bronchoconstriction in response to a variety of stimuli; bronchospasm may be elicited during induction and maintenance of anaesthesia. The prevalence of BHR in normal populations is approximately 10%. BHR is an important feature of clinical asthma, chronic obstructive pulmonary disease (COPD), allergic rhinitis, atopy, upper respiratory tract infections and smoking. This review will outline some important aspects of the pathophysiological basis of BHR, i.e., neural and inflammatory mechanisms. Furthermore, it should assist in identifying patients at risk and update perioperative anaesthetic considerations. Prophylaxis of airway reflex activation and an appropriate anaesthetic plan should prevent airway constriction. Since tracheal intubation is the major risk factor to induce bronchospasm intubation should be avoided whenever possible and regional anaesthesia preferred. If tracheal intubation is unavoidable, propofol and ketamine can be recommended as induction agents. Prophylaxis of intraoperative bronchospasm and initial therapy, such as deepening of anaesthesia, inhalational administration of sympathomimetics and anticholinergics, and i.v. use of local anaesthetics and corticosteroids are outlined. Despite its popularity theophylline offers little benefit during anaesthesia. Adequate preoperative evaluation and preparation of the patient with BHR will contribute to optimising anaesthetic management of patients with BHR.

Anesthesia↗

PubMed1998

[Histamine plasma concentration and cardiovascular effects of non-depolarizing muscle relaxants: comparison of atracurium, vecuronium, pancuronium and pipecuronium in coronary surgical patients at risk].

OBJECTIVE: Cardiovascular effects of four commonly used non-depolarising muscle relaxants and their ability to increase histamine plasma concentrations were studied in patients scheduled for coronary artery bypass grafting. METHODS: 40 patients were included in the study after informed consent. After premedication with Flunitrazepam (2 mg p.o.) on the evening before and 1 hour prior to surgery anaesthesia was induced with Flunitrazepam (4-6 micrograms kg-1). Fentanyl (3 micrograms kg-1) und Etomidate (150 micrograms kg-1) and the patients were ventilated via face mask with 50% N2O in oxygen. Patients were randomly allocated to one of four groups, and, 15 min after induction of anaesthesia, received equipotent doses of either Pancuronium (0.09 mg kg-1, n = 10). Pipecuronium (0.08 mg kg-1, n = 10), Atracurium (0.6 mg kg-1, n = 10), or Vecuronium (0.1 mg kg-1, n = 10) injected over 20 seconds via a central venous catheter. Cardiovascular variables were determined in the awake patient, 15 min after induction of anaesthesia and following administration of the respective muscle relaxant. In addition, plasma histamine concentrations were assessed before and after relaxation. Evoked muscular response to TOF simulation of the ulnar nerve (plethysmo-mechanogram) was continuously recorded to determine the onset of neuromuscular blockade. RESULTS: Heart rate, mean arterial pressure and cardiac index significantly decreased in all patients following induction of anaesthesia while systemic vascular resistance remained unchanged. Only Pancuronium caused a significant increase in heart rate (53 +/- 11 to 61 +/- 15 min-1) whereas cardiac index and mean arterial pressure did not change significantly. No other neuromuscular blocking agent caused any changes in the cardiovascular variables measured and histamine plasma concentrations remained within the reference range in all of the four groups with no differences detectable between groups. CONCLUSIONS: All investigated neuromuscular blocking agents exhibited marked cardiovascular stability which permits their use, being based exclusively on pharmacodynamic and pharmakokinetic considerations even in patients with coronary heart disease. If an increase in heart rate appears beneficial Pancuronium may be advantageous.

Anesthesia↗

PubMed1998

[Postoperative nausea and emesis: mechanisms and treatment].

The incidence of postoperative emetic symptoms in patients varies between 3 and 91%. Nausea and emesis remain the most common as well as unpleasant side-effects experienced by patients following general anaesthesia, both in the ambulatory and non-ambulatory care setting. Furthermore, emesis carries the risk of severe postoperative complications and is associated with additional costs. Multiple factors are associated with an increased risk of developing postoperative nausea and emesis including age, gender, weight, preexisting disease, as well as anaesthetic and surgical procedures. Routine antiemetic prophylaxis is not currently advisable in patients with a low Emesis Risk, due to undesirable side-effects of antiemetics and additional costs. However, anti-emetic prophylaxis is recommended for patients with an increased risk. Besides administration of antiemetics, other factors that may provoke postoperative emesis need to be considered such as gastric distension, early mobilisation, insufficient analgesia, choice of anaesthetic drugs. High-risk patients may be anaesthetized with propofol, if possible. If symptoms do develop in the recovery room, tight fitting oxygen masks should be avoided and adequate hydration and analgesia ensured. To avoid side effects, antiemetics should be administered in minimally effective dosages. If emesis persists, combination of antiemetic drugs with different profiles of receptor action may be particularly useful.

Anesthesia↗

PubMed1998

Barriers to care among persons living with HIV/AIDS in urban and rural areas.

People living with HIV disease, particularly those in small towns and rural areas, face many barriers that prevent them from receiving important life-care services. We developed the Barriers to Care Scale (BACS) to delineate the problem severity of factors that impede care and service provision among a sample of 226 men and women living with HIV disease in a single midwestern state. Both urban and rural respondents indicated that major barriers to life-care services included the lack of knowledge about HIV among citizens in the community, insufficient personal financial resources, the lack of employment opportunities for people living with HIV, and the lack of supportive and understanding work environments. Rural persons living with HIV disease, compared to their urban counterparts, assigned significantly higher problem severity ratings to the following barriers: the need to travel long distances to medical facilities and personnel; a shortage of adequately trained medical and mental health professionals; a lack of personal or public transportation; and community residents' stigma toward people living with HIV. The large number of barriers to care identified in the present study indicates that innovative programmes designed to remove these barriers and improve the life quality of rural persons living with HIV are urgently needed.

Acquired Immunodeficiency Syndrome↗

PubMed1998

Effect of positive end-expiratory pressure on the incidence of venous air embolism and on the cardiovascular response to the sitting position during neurosurgery.

We have studied prospectively the effect of 10 cm H2O of PEEP on the incidence of venous air embolism and on the cardiovascular response to change from the supine to the seated position in a large neurosurgical population. Patients were allocated randomly to receive either PEEP (10 cm H2O, n = 45) or conventional (control, n = 44) ventilation. Cardiovascular and respiratory variables were measured in the supine and sitting positions, and monitoring included precordial Doppler probe, pulmonary artery pressure and expiratory carbon dioxide concentration. Venous air embolism was assumed if changes in precordial Doppler sounds occurred, end-tidal carbon dioxide concentration decreased or air could be retrieved from a central venous multi-orifice catheter. The incidence of venous air embolism (26%) did not differ between patients undergoing conventional ventilation and those undergoing ventilation with 10 cm H2O of PEEP. Venous air embolism was always detected first by alterations in Doppler sounds. Cardiac output was significantly higher in patients undergoing conventional ventilation than in those undergoing ventilation with PEEP in the supine but not in the sitting position. Furthermore, pulmonary vascular resistance increased significantly only in the upright position in those undergoing ventilation with PEEP. The pulmonary artery wedge pressure to central venous pressure gradient did not attain negative values with PEEP or with upright positioning. We conclude that the use of PEEP during neurosurgical procedures performed in the sitting position should be abandoned as it does not decrease the incidence of venous air embolism but is associated with significant adverse cardiovascular effects.

Adolescent↗

PubMed1998

Pharmacokinetic interaction between oral cyclosporin and mibefradil in stabilized post-renal-transplant patients.

BACKGROUND: The potential for interaction between oral cyclosporin (Sandimmun) and the new calcium antagonist mibefradil was assessed as part of the clinical development of the new compound. METHODS: Six stable renal transplant patients on long-term, oral, twice-daily (Q 12 H) cyclosporin (CsA) therapy received 25 mg mibefradil on Day 1, followed by 50 mg once daily for 5 or 6 days. At baseline, as well as on the last day of mibefradil dosing, complete steady-state CsA blood concentration-time profiles were characterized over a dosing interval. RESULTS: Mibefradil led to mean increases in minimum and maximum CsA blood concentrations and area under the curve of CsA by 2.7-, 2.1-, and 2.3-fold, respectively (all significantly different from CsA alone, P < 0.02). Mibefradil is therefore associated with a clinically relevant increase in CsA blood concentrations. The mechanism of elevation of CsA blood concentrations is probably mibefradil and/or metabolite inhibition of the cytochrome P-450 isoenzyme 3A4. CsA had no clinically significant effect on mibefradil plasma concentrations. CONCLUSIONS: These results confirm previous findings of cytochrome P-450 3A4 inhibition by mibefradil and suggest that, for patients receiving CsA, its dose must be adjusted and its plasma concentration must be monitored when adding or stopping mibefradil.

Administration, Oral↗

PubMed1998

Profound increase in epinephrine concentration in plasma and cardiovascular stimulation after mu-opioid receptor blockade in opioid-addicted patients during barbiturate-induced anesthesia for acute detoxification.

BACKGROUND: Acute displacement of opioids from their receptors by administration of large doses of opioid antagonists during general anesthesia is a new approach for detoxification of patients addicted to opioids. The authors tested the hypothesis that mu-opioid receptor blockade by naloxone induces cardiovascular stimulation mediated by the sympathoadrenal system. METHODS: Heart rate, cardiac index, and intravascular pressures were measured in 10 patients addicted to opioids (drug history; mean +/- SD, 71 +/- 51 months) during a program of methadone substitution (96 +/- 57 mg/day). Cardiovascular variables and concentrations of catecholamine in plasma were measured in the awake state, during methohexital-induced anesthesia (dose, 74 +/- 44 microg x kg(-1) x min(-1)) before administration of naloxone, and repeatedly during the first 3 h of mu-opioid receptor blockade. Naloxone was administered initially in an intravenous dose of 0.4 mg, followed by incremental bolus doses (0.8, 1.6, 3.2, and 6.4 mg) at 15-min intervals until a total dose of 12.4 mg had been administered within 60 min; administration was then continued by infusion (0.8 mg/h). RESULTS: Concentration of epinephrine in plasma increased 30-fold (15 +/- 9 to 458 +/- 304 pg/ml), whereas concentration of norepinephrine in plasma only increased to a minor extent (76 +/- 44 to 226 +/- 58 pg/ml, P < 0.05). Cardiac index increased by 74% (2.7 +/- 0.41 to 4.7 +/- 1.7 min(-1) x m(-2)), because of increases in heart rate (89 +/- 16 to 108 +/- 17 beats/min) and stroke volume (+44%), reaching maximum 45 min after the initial injection of naloxone. In parallel, systemic vascular resistance index decreased (-40%). Systolic arterial pressure significantly increased (113 +/- 16 to 138 +/- 16 mmHg), whereas diastolic arterial pressure did not change. CONCLUSIONS: Despite barbiturate-induced anesthesia, acute mu-opioid receptor blockade in patients addicted to opioids induces profound epinephrine release and cardiovascular stimulation. These data suggest that long-term opioid receptor stimulation changes sympathoadrenal and cardiovascular function, which is acutely unmasked by mu-opioid receptor blockade. Because of the attendant cardiovascular stimulation, acute detoxification using naloxone should be performed by trained anesthesiologists or intensivists.

Adult↗

PubMed1998

Combined intravenous lidocaine and inhaled salbutamol protect against bronchial hyperreactivity more effectively than lidocaine or salbutamol alone.

BACKGROUND: Airway instrumentation in persons with asthma is linked to the risk of life-threatening bronchospasm. To attenuate the response to airway irritation, intravenous lidocaine is recommended (based on animal experiments) and mitigates the response to histamine inhalation in asthmatic volunteers. However, the effects of lidocaine have not been compared with standard prophylaxis with beta-sympathomimetic aerosols. Therefore, the effect of lidocaine, salbutamol, combined treatment, and placebo control were tested in awake volunteers with bronchial hyperreactivity. METHODS: After approval from the local ethics committee, 15 persons, who were selected because they showed a decrease in forced expiratory volume in 1 s (FEV1) more than 20% of baseline in response to inhaled histamine in a concentration less than 18 mg/ml (PC20), were enrolled in a placebo-controlled, double-blind, and randomized study. The challenge was repeated on four different days and the volunteers were pretreated with either intravenous lidocaine, inhalation of salbutamol, inhalation of salbutamol plus intravenous lidocaine, or placebo. Lidocaine plasma concentrations were also measured. Statistical analyses included the Friedman test and Wilcoxon's rank sum. RESULTS: The baseline PC20 was 6.4 +/- 4.3 mg/ml. Intravenous lidocaine and salbutamol aerosol both significantly increased the histamine threshold to 14.2 +/- 9.5 mg/ml and 16.8 +/- 10.9 mg/ml, respectively (mean +/- SD). However, the combination of lidocaine and salbutamol significantly increased the PC20 even further to 30.7 +/- 15.7 mg/ml than did salbutamol or lidocaine alone. CONCLUSIONS: In volunteers with bronchial hyperreactivity, both lidocaine and salbutamol attenuate the response to an inhalational histamine challenge, and their combined administration has much greater effects than does either drug alone. Accordingly, pretreatment of patients with bronchial hyperreactivity with both beta-mimetic aerosol and intravenous lidocaine is recommended before airway irritation.

Administration, Inhalation↗

PubMed1998

Transient evoked otoacoustic emissions in patients with normal hearing and in patients with hearing loss.

OBJECTIVES: 1) To evaluate transient evoked otoacoustic emission (TEOAE) test performance when measurements are made under routine clinical conditions. 2) To evaluate TEOAE test performance as a function of frequency and as a function of the magnitude of hearing loss. 3) To compare test performance using univariate and multivariate approaches to data analyses. 4) To provide a means of interpreting clinical TEOAE measurements. DESIGN: TEOAEs were measured in 452 ears of 246 patients. All measurements were made after acoustic immittance assessments, which were used to demonstrate that middle-ear function was normal at the time of the TEOAE test. TEOAE amplitudes and signal to noise ratios (SNRs), analyzed into octave bands centered at 1, 2, and 4 kHz, were compared with the pure-tone threshold at the same frequencies. Data were analyzed with clinical decision theory, cumulative distributions, discriminant analyses, and logistic regressions. RESULTS: Using univariate analysis techniques, TEOAEs accurately identified auditory status at 2 and 4 kHz but were less accurate at 1 kHz. Test performance was best when audiometric thresholds between 20 and 30 dB HL were used as the criteria for normal hearing. TEOAE SNR resulted in better test performance than did TEOAE amplitude alone; this effect decreased as frequency increased. Multivariate analysis methods resulted in better separation between normal and impaired ears than did univariate approaches, which relied on only TEOAE amplitude or SNR when test frequency band and audiometric frequency were the same. This improvement in test performance was greatest at 1 kHz, decreased as frequency increased, and was negligible at 4 kHz. CONCLUSIONS: TEOAEs can be used to identify hearing loss in children under routine clinical conditions. Univariate tests accurately identified auditory status at mid and high frequencies but performed more poorly at lower frequencies. The decrease in performance as frequency decreases may be a result of increased noise at lower frequencies but also may be due to properties of the measurement paradigm ("QuickScreen," high-pass filter at 0.8 kHz), which would not be ideal for recording energy around 1 kHz. The improvement in test performance when SNR was used and the interaction of this effect with frequency, however, would be consistent with the view that test performance in lower frequencies is at least partially influenced by the level of background noise. Multivariate analysis techniques improved test performance compared with the more traditional univariate approaches to data analysis. An approach is provided that allows one to assign measured TEOAE amplitudes, SNRs, or outputs from multivariate analyses to one of three categories: response properties consistent with normal hearing; results consistent with hearing loss; hearing status undetermined.

Acoustic Stimulation↗

PubMed1998

Uterine cervical dysplasia and cancer: identification of c-myc status by quantitative polymerase chain reaction.

The c-myc oncogene status was determined in patients with nondysplasia (ND; 9 patients), low-grade squamous intraepithelial lesion (LGSIL; 12 patients), high-grade squamous intraepithelial lesion (HGSIL; 21 patients) and invasive squamous cell carcinoma (ISCC; 20 patients) of uterine cervix using fluorescent quantitative polymerase chain reaction (PCR). In the same paraffin-embedded specimens, other potential risk factors were also screened: human papillomavirus (HPV) infection, Ha-ras codon 12 mutation, DNA aneuploidy. Gene amplification, identified as c-myc copy numbers greater than the mean value +2 SD of patients with ND, was seen in 44% patients with LGSIL, 76% patients with HGSIL, and 67% patients with ISCC. These data indicate that c-myc amplification is one of the critical early events in the progression of uterine cervical lesions. HPV infection of various subtypes was identified in 0% patients with ND, 55% patients with LGSIL, 95% patients with HGSIL, and 84% patients with ISCC. No codon 12 mutation of the Ha-ras gene was found in this series. Aneuploid DNA pattern was seen in 0% patients with ND, 58% patients with LGSIL, 90% patients with HGSIL, and 80% patients with ISCC. There was a significant correlation between HPV infection and DNA aneuploidy. However, no relationship was seen between c-myc status and other factors in this series. Patients with HGSIL and ISCC almost always (95%) had multiple risk factors, whereas more than half of the patients with LGSIL had no or only one risk factor (P = 0.0001).

Aneuploidy↗

PubMed1998

Economic burden of environmental tobacco smoke on Hong Kong families: scale and impact.

STUDY OBJECTIVE: To examine the financial cost of doctor consultations for cough, phlegm, and wheeze in children living in a home where family members smoke compared with those not exposed to environmental tobacco smoke. To model these costs to provide the Territory of Hong Kong with estimates of potentially avoidable health care resource use. DESIGN: Cross sectional questionnaire survey. SUBJECTS AND SETTING: All children (10,615) in classes primary 3 to 6 (aged 8-13 years) attending 27 schools in two districts of Hong Kong in 1992 and their parents. MEASUREMENTS AND MAIN RESULTS: Doctor consultations during the previous three months for symptoms of either cough, phlegm or wheeze were higher in younger children, ranging from 22.9% in 8 year olds to 8.4% in those aged 12 or over. For those children living in homes with one, or more than one, smoker category (there were four categories of smokers: father, mother, siblings, others), the adjusted odds ratios (95% confidence intervals) for a doctor consultation for any of these symptoms were 1.15 (1.01, 1.31) and 1.38 (1.14, 1.67) respectively. Using US$15 as the minimum cost incurred per consultation, the expected direct cost per annum per child of doctor consultations was 14% higher for children living in a one smoker category home and 25% for two or more compared with exposure to no smokers in the home. Using these values on a territory wide basis, the annual avoidable direct cost associated with exposure to tobacco smoke in children from birth to 12 years of age ranged from US$338,042 to US$991,591. CONCLUSIONS: Exposure to environmental tobacco smoke not only provides a respiratory health risk for children but also an avoidable excess cost to the family's financial resources and health service providers.

Child↗

PubMed1998

Comparison between two districts of the effects of an air pollution intervention on bronchial responsiveness in primary school children in Hong Kong.

STUDY OBJECTIVE: This study examined the impact on children's respiratory health of a government air quality intervention that restricted the sulphur content of fuels to 0.5% from July 1990 onwards. DESIGN/SETTING/PARTICIPANTS: This study examined the changes, one and two years after the introduction of the intervention, in airway hyperreactivity of non-asthmatic and non-wheezing, primary 4, 5, and 6, school children aged 9-12 years living in a polluted district compared with those in a less polluted district. Bronchial hyperreactivity (BHR)(a 20% decrease in FEV1 provoked by a cumulative dose of histamine less than 7.8 mumol) and bronchial reactivity slope (BR slope) (percentage change in logarithmic scale in FEV1 per unit dose of histamine) were used to estimate responses to a histamine challenge. The between districts differences after the intervention were studied to assess the effectiveness of the intervention. MAIN RESULTS: In cohorts, comparing measurements made before the intervention and one year afterwards, both BHR and BR slope declined from 29% to 16% (p = 0.026) and from 48 to 39 (p = 0.075) respectively in the polluted district; and from 21% to 10% (p = 0.001) and 42 to 36 (p > 0.100) in the less polluted district. Comparing measurements made in 1991 (one year after intervention) with those in 1992 (two years after intervention), only the polluted district showed a significant decline from 28% to 12% (p = 0.016) and from 46 to 35 (p = 0.014), for BHR and BR slope respectively, with a greater decline in both responses (p = 0.018 and 0.073) than in the less polluted district. CONCLUSION: Bronchial hyperresponsiveness tests can be used to support the evaluation of an air quality intervention. The demonstrated reduction in bronchial hyperresponsiveness is an indication of the effectiveness of the intervention.

Air Pollutants↗

PubMed1998

Localisation of the imprinted gene neuronatin, Nnat, confirms and refines the location of a second imprinting region on mouse chromosome 2.

Nine regions on six mouse autosomes are subject to imprinting and uniparental inheritance of any one of these regions results in mice with phenotypic anomalies. So far on distal Chromosome (Chr) 2 there is a unique imprinting region between 2H3 and 2H4 associated with two behavioural disorders and neonatal lethality. A maternally imprinted gene, Nnat, has been identified which is expressed in the nervous system and maps to distal Chr 2. Nnat has been excluded as a candidate for either or both the behavioural phenotypes as it lies proximal to the 2H3-2H4 imprinting region. Here we have mapped Nnat to band 2H1 which is at least 18 Mb proximal to the previously described imprinting region. It maps close to agouti, some alleles of which show differential expression according to parental origin. The localisation of Nnat to band H1 confirms and refines the map location of a second imprinting region on mouse Chr 2.

Animals↗

PubMed1998

Specific regulation of StAR expression in the rat adrenal zona glomerulosa. An in situ hybridization study.

Steroid acute regulatory protein (StAR) plays an essential role in steroidogenesis because it is responsible for the transfer of cholesterol from cellular stores to the inner mitochondrial membrane. We investigated the distribution and regulation of StAR expression in association with aldosterone production in the rat adrenal gland in vivo. Using nonradioactive in situ hybridization, we demonstrate that the outermost five to seven parenchymal cell layers express the StAR gene only weakly and inhomogeneously. The strongest expression is found in the zona fasciculata and zona reticularis. In addition, some cells in the adrenal medulla also stained positively. To differentiate between functionally active glomerulosa and inactive intermediate cells, we compared the expression pattern of StAR with that of aldosterone synthase. The expression of the latter is localized to two or three cell layers only, located immediately below the capsule. However, the cells of the intermedia are capable of expressing both genes prominently, as shown after stimulation with bilateral nephrectomy for 2 days. All zones of the adrenal cortex by then expressed StAR gene to the same extent. This was accompanied by a 50-fold elevated plasma aldosterone concentration. Our data demonstrate that the width of the aldosterone-producing zone can increase within a short period of time by recruiting hormonally inactive cells to steroidogenesis.

Adrenal Cortex↗

PubMed1998

T cells infiltrating the skin of Tsk2 scleroderma-like mice exhibit T cell receptor bias.

The T cell repertoire expressed by Tsk2 mice, a novel experimental model of systemic sclerosis, was examined to determine whether cells infiltrating the areas of involved skin exhibit a T cell receptor (TCR) bias. Reverse transcription-polymerase chain reactions (RT-PCR) were conducted using RNA extracted from lymph nodes and skin from TSk2 mice and from normal mice, with an oligonucleotide primer library specific for the variable region of the TCR (beta) chain. RT-PCR signals were observed in all lymph node cell (LNC) samples from both Tsk2 mice and control mice, with eighteen of the twenty-one Vbeta types present. In contrast, cDNA extracted from areas of involved skin from Tsk2 mice exhibited a restricted pattern, with positive Vbeta signals corresponding to eight T cell subtypes (Vbeta1, 6, 8.1, 8.2, 10, 11, 16, and 18). Band strength analysis revealed that three Vbeta subtypes dominated within this restricted pattern (Vbeta8.1, 11, and 18). Moreover, this pattern of Vbeta bias was consistent among the four skin samples from different Tsk2 mice. These data suggest that a restricted T cell population participates in the inflammatory cell infiltrate of Tsk2 skin.

Animals↗

PubMed1998

Differential development of early hypertension in heterozygous transgenic TGR(mREN2)27 rats.

The aim of the study was to determine blood pressures in young heterozygous transgenic rats harbouring the Ren-2 mouse gene, TGR(mREN2)27, and to examine the association between blood pressure and plasma renin-angiotensin parameters during the conscious state. Two litters of heterozygous TGR(mREN2)27 rats and their normotensive Sprague-Dawley reference animals were bred in our laboratory. Cardiovascular phenotypes and blood, for the evaluation of plasma renin-angiotensin-system parameters, were obtained via arterial catheters in conscious rats 4 weeks after birth. Blood pressure values showed a high degree of interindividual variability and significant litter differences in the group of transgenic animals ranging from normotensive tohypertensive values. Plasma prorenin levels were markedly increased in TGR(mREN2)27, whereas both active renin and angiotensin II plasma concentrations were reduced independently from hypertension. Plasma prorenin levels in litter 2 of transgenic animals which exhibited significantly elevated blood pressures were significantly higher as compared to those of litter 1 which showed blood pressures that were not significantly different from SD. These data demonstrate that the development of hypertension in heterozygous TGR(mREN2)27 takes place in the fourth week of postnatal life and exhibits large interindividual variability. Moreover, development of early hypertension in young heterozygous TGR(mREN2)27 is associated with higher plasma prorenin levels.

Animals↗

PubMed1998

[Bronchial carcinoma developing in a tuberculous scar: computer tomographic follow up].

The development of scar is a rare complication of lung tuberculosis which was yet not often demonstrated in the radiologic literature. We report on a 71 year old male suffering by lung tuberculosis in an active stage which developed lung cancer in the region of tuberculotic scar clearly depicted on computed tomography. To the best of our knowledge this is the first reported computed computed tomography control series dealing with this problem. Additionally we report on histopathologic findings showing an early cancer in the surrounding of a tuberculotic scar.

Aged↗

PubMed1998

[Effect on the microbicidal efficacy of formaldehyde, glutardialdehyde, peracetic acid, chloramine T (N-chloro-4-toluenesulfonamide), m-cresol, ethanol and benzyldimethyldodecacylammonium bromide by blood (model experiments for chemical disinfection of instruments)].

In a preceding paper (Zbl. Hyg. 191 [1991] 457-477) we reported on the dependence of the microbicidal efficacy of active agents of the disinfection of instruments on the amount of coagulated blood adhering to the instruments. In the present investigation, we were interested in the dependence of the microbicidal effects on the amount of blood in the solutions of the active agents. Test areas of 2 cm2 were contaminated with 50 and 100 microliters coagulating blood, respectively, containing cells of Staphylococcus aureus as test germ. The solutions of the microbicidal agents were contaminated with heparinized blood up to a concentration of 4% immediately before starting the disinfection and 24 hours before, respectively. After a period of action lasting 1 hour at 20 degrees C, the relative number of test germs capable of multiplying (N/N0) was determined. The concentration of the microbicidal substances reducing the relative number of test germs capable to multiply to 10(-4) served for estimating the dependence of the microbicidal efficacy of the agents on the blood content of the solutions. The experimental results depended on the thickness of the layer of coagulated blood. The dependence of the efficacy of the microbicidal substances on the blood content of the solutions was the higher the thinner the blood layer was. At a thickness of the layer of the coagulated blood of 0.25 mm, a blood content of the solution of 4%, and applying it immediately after adding the blood, the concentration of glutardialdehyde had to be 1.6 times that without blood to reach the same microbicidal efficacy. When applying the solution 24 hours after adding the blood, the concentration of glutardialdehyde had to be 4.2 times that without blood. The quaternary ammonium compound reacted faster with the blood than did glutardialdehyde; the respective factors were 2.6 and 4.5. The concentration factors of chloramine T were 3.3 and 3.8. Under the conditions of the test, peracetic acid exhibited small concentration factors: 1.3 and 1.6. The microbicidal efficacy of ethanol, formaldehyde and m-cresol soap solution was not or only slightly altered by the amount of blood in the solution of the microbicidal agent.

Benzalkonium Compounds↗